Field of the Disclosure
The present disclosure relates to a power-supplying device, and a wireless power-supplying system.
Description of Background Art
Japanese Unexamined Patent Application, First Publication No. 2010-252446 discloses a wireless power-supplying system capable of simplifying a power-supplying device and a power-receiving device. In this wireless power-supplying system, the power-supplying device estimates a distance between its own primary self-resonance coil and a secondary self-resonance coil of the power-receiving device and controls supply of electric power depending on the distance. Thus, it is not necessary to estimate the distance by performing communication with the power-receiving device. That is, since a communication function is not necessary, configurations of the power-supplying device and the power-receiving device can be simplified. Further, as a related technology, Japanese Unexamined Patent Application, First Publication No. 2005-006459 discloses a wireless power device in which prevention of damage of a part of a power-receiving device or prevention of heat generation in the part is achieved when a load of the power-receiving device is in an open state or when the power-receiving device is used in a low-load state. A load detection and power transfer control device detects whether a load to be connected to the power-receiving device is a non-load or a low load, and decreases an oscillation frequency of an oscillation circuit of the power transfer device to a predetermined value when the load is non-load or a low load. Accordingly, it is possible to decrease an output voltage of the power-receiving device and prevent adverse effects due to abnormality of the load. Further, as another related art, Japanese Unexamined Patent Application, First Publication No. H08-080042 discloses a technology capable of preventing a resonance voltage VC from exceeding a breakdown voltage level of an FET or the like, and preventing voltage damage or lifespan shortening of an element since a resonance voltage VC can be made constant even when a level of a load has changed.